1. Field of the Invention
The present invention generally relates to an office product, electric pencil sharpener, more particularly the present invention relates to an improved electric pencil sharpener provided with a feeding subassembly with a pair of feeding rollers, which space between the two feeding rollers is automatically adjustable. A further novel element of the invention is the provision for an electric pencil sharpener capable of automatic sharpening and feeding different pencils with different sizes.
2. Background of the Invention
Pencil sharpener is a necessary tool in the modern office. Electric pencil sharpeners are in widespread use largely due to their modest price and outstanding reliability. A typical electric pencil sharpeners comprises an electric motor, a gear train, a cutter assembly, and a receptacle receiving a pencil or a pencil alignment subassembly, and a switch for activating the motor, e.g. upon insertion of a pencil. When the pencil is positioned in the receptacle, the motor exports its power to the cutter assembly through the gear train. The pencil is sharpened by a blade of the cutter assembly. Numerous innovations for pencil sharpeners have been provided in the prior art that will be described.
A typical pencil sharpener is presented, in cross reference to applicant's related application, U.S. application Ser. No. 11/602,252, filed on the date Nov. 21, 2006, which teaches an improved electric pencil sharpener. The aforementioned improved electric pencil sharpener includes a motor, a transmission subassembly engaged with the motor, a cutter subassembly and a feeding subassembly and an enclosure holding all the components. The cutter assembly and the feeding subassembly are driven by the transmission subassembly. Said feeding subassembly includes a feeding gear set and a pair of feeding rollers driven by the feeding gear set. The interval between the two feeding rollers is adjusted under an adjusting subassembly with complicated structure. The adjusting subassembly includes a cage forming an inner path thereinside, a cap covering one end portion of the cage, a pair of bracket standing on the enclosure defining an interior space, and two adjusting block arranged on respective brackets. The cage encompasses the brackets and the interior space. Each of the feeding rollers is fixed a shaft supported between the two brackets and getting through slide ways defined in each of the brackets. The adjusting blocks are respectively attached to the two axes carrying feeding rollers at the point where the axes sticking out the interior space from the brackets. Each of the adjusting blocks combines an adjusting rod. A spring is squeezed between the cap and the adjusting rods so as to urge the adjusting rods to ride along the path inside the cage in close proximity. When sharpening pencils with different diameter, rotate the cap, the adjusting rods ride along the path to push the axes carrying feeding rollers moving back or forth, thereby changing the interval between the two feeding rollers under restriction of the slide ways in the pair of brackets. However, the adjusting assembly in the conventional electric pencil sharpener is so sophisticated, that results in high manufacturing cost. Moreover, the interval adjustment between the two feeding rollers is under manual operation, which is inconvenient for people to operate such electric pencil sharpener.
In light of the foregoing, there is a very desirable need to improve the typical electric pencil sharpener.